Field of Invention
The present invention relates to a camera module, and more particularly to an electrical bracket and a circuit conducting method for a camera module.
Description of Related Arts
With the rapid development of electronic products, the electronic products become a vital product in people daily lives. In order to achieve the market demands of space-saving and portability, the electronic products are designed to have a tendency toward lightness and thinness, such that the size of each electronic component must be minimized. Therefore, the size of the camera module must also be minimized with lightness and thinness features correspondingly to be installed into the electronic product.
In order to enhance the camera module pixel accuracy and function, the size of the chip area will be relatively increased to couple with increasing numbers of different drivers, resistors, capacitors and other electronic components. In other words, the packaging size of the camera module will be increased as well. In particular, this is always a conflict between an existing mobile phone module package and the trend of phone camera module with its thinness and miniaturization features, it is necessary to invent a new type of compact packaging technology to meet the demands of product development.
Camera module structure in the traditional COB (chip on board) manufacturing process comprises a printed circuit board, a photosensitive sensor, a lens base, a driver driver, and a lens assembly, wherein each of the electronic components of the camera module structure are arranged on a surface of the circuit board, wherein the electronic components are not overlapped with each other. Based on the high requirement of pixel and extra-thin structure of the camera module, the image quality for the camera module is highly expected. Therefore, the packaging and assembling process of the camera module will be complicated and the specification of each electronic component will be relatively high. At the same time, for higher pixel of the camera module, the chip area thereof becomes relatively bigger. The number of electronic components, such as the driver driver, resistors, and capacitors, will be increased. As a result, the overall size of the camera module will be relatively enlarged.
Currently, the design for portable electronic devices, such as smart phones and tablet PCs, has shown a general tendency toward lightness and thinness, which requires various compact sized components of the portable electronic device (especially refers to the thickness of the components) to be more compact by further reducing the sizes thereof. For example, the camera module as a standard component in a portable electronic device has tendency toward lightness and thinness to be installed in the portable electronic device.
Existing mobile phone module package is conflict with the trend of phone camera module with its thinness and miniaturization features, it is necessary to invent a new type of compact packaging technology to meet the demands of product development.
Referring to FIG. 1, a camera module in a prior art is illustrated, wherein the camera module comprises an optical lens 1, a driver 2, an optical filter 3, a base 4, at least one metal wire 5, a drive control member 6, a circuit board 7, a photosensitive chip 8, at least one driver solder joint 9 and a conductor used for electrically connecting the driver 2 and the circuit board 7. The photosensitive chip 8 is attached on the top surface of the circuit board 7. The metal wire 5, such as copper wire, is used to connect the photosensitive chip 8 and the circuit board 7 by wire bonding. The optical filter 3 is attached to the base 3 or the optical lens 1. After the camera module is assembled, the driver pins are soldered in order to electrically connect to the driver 2 and the circuit board 7. So, the circuit board 7 can provide power to the driver 2 and further control the operation of the driver 2.
Although such camera module has been widely used in the market, this camera module still has many drawbacks.
Firstly, the driver 2 has a protruded conductor which is electrically connected to the circuit board 7, so that the driver 2 is electrically connected to the circuit board 7. The conductor is connected to the circuit board 7 through the solder joint 9. The process to connect the driver 2 and the circuit board 7 through a protruded conductor is complicated, and will generate many other problems, such as the product quality might be influenced by the soldering quality. Moreover, this soldering connection by soldering the protruded conductor is not solid, which would be easily damaged during operation or maintenance process.
Furthermore, the circuit board 7 and the photosensitive chip 8 are connected by the metal wire 5. Such electrical connection is not secured. In addition, the base 4 needs to provide a relative large protection space for the metal wire 5 to be securely set. In other words, the size of the base 4 will be enlarged. Accordingly, the size of the entire camera module will also be enlarged.
Furthermore, the conductor, the metal wire 5 and the drive control module 6 are vulnerable to external environment, such as the dust, etc., so as to affect the quality of the entire camera module and to reduce the service life of the entire camera module.
Furthermore, in order to provide a better supporting function of the base, the size of the base must be enlarged to provide a larger supporting area. Therefore, the overall size of the camera module will become larger as well. If the size of the camera module is reduced by reducing the size of the base, the supporting function of the base will be affected.
Furthermore, the circuit board of the conventional camera module is mounted on a bottom portion of the camera module, wherein the energy consuming components, such as the driver and the photosensitive sensor, are arranged in a relatively far distance from the circuit board. In other words, more wires are required to be used in the camera module for electrical connection, and the design of the circuit configuration for the electrical components is more complicated. As a result, the occupying space of the circuit cannot be reasonably utilized. That is to say, if the circuit configuration and the electrical components are reasonably re-designed, the occupying space of the circuit can be effectively minimized. Then, the dimension of the camera module can be further minimized. Of course, the dimension, such as the width or thickness, of the camera module can be selectively adjusted in order to satisfy the market demands.
Accordingly, conventional mobile phone camera module utilizes chip-scale package technology (CSP) or chip-on-board assembly technology (COB), in which each electronic component is placed on the surface of the circuit board, which does not overlap each other between the electronic components. In an autofocus camera module, in order to protect the chip which is placed on the surface of the circuit board, the support is often needed to protect the internal components and to support the driver. With the increasing demand of camera module pixel accuracy and function, the use of different drivers, resistors, capacitors and other electronic components will be correspondingly increased, which will result in the increase of the chip area and the increasing packaging size of the camera module.
As mentioned above, the connection between the circuit board 7 and the photosensitive chip 8 together with the connection between the driver 2 and the circuit board 7 that both takes certain large space and are difficult to get good protection. At the same time, the base 4 has a large size to be connected with the circuit board 7, the photosensitive chip 8 and the driver 2. However, it can achieve electrical connection between the circuit board 7 and the driver 2 and between the circuit board 7 and the photosensitive chip 8. In addition, the base 4 is hardly able to provide enough protection to other electronic components in the camera module.
Accordingly, the photosensitive sensor circuit for the conventional camera module is electrical conducted via a chip pad by coating a gold protrusion or gold wire to electrically connect to the circuit board. Therefore, the manufacturing cost and the yield of the camera module are affected by the gold protrusion or the gold wire.
According to the development of the high pixel camera module, the number of the chip pads of the photosensitive sensor has become more and more, and clearance spaces between the chips pad will become smaller and smaller, so the manufacturing process of the high pixel camera module will be very difficult and complicated.
In order to achieve a better conduction of the circuit of the camera module, the present invention provides a first connection arrangement and a conduction method for the camera module, wherein different electrical components within the camera module can be electrically connected through the first connection arrangement and the conduction method. For example, the photosensitive sensor and the electrical bracket of the camera module can be electrically connected through the first connection arrangement and the conduction method.